"Since the advent of full-time referees, the pre-seasons are a lot different and very much at NRL level, like that of a club with the players," Clark said.

"When we're talking about kids in our development academies, a lot of the kids will be still at school, studying at uni or working, so they do it in addition to all their normal commitments, so it's extra hard.

"Preseason for these country kids is not unlike what I envision it's like for country players.

"It's a big commitment but they're very keen and interested and willing to do as much as they can to try and make it to the top one day."

More than 120 CRL referees, old and young, attended the three-day seminar that involved both rules presentations and physical drills.

A host of leading NRL referees were on hand, including Ben Cummins and Ashley Klein.

"We're putting them through some physical testing, some laws-based presentations and some general presentations on what makes a good referee," Clark said.

"Some are part of our elite pathway and it's in our long-term interest to develop as many of these kids as we can, so hopefully one day they can make the NRL.

"These kids also go back to grassroots footy in the country and that's where they learn and other referees can learn from them and hopefully some of them will make it to the top."

Rules rarely stay the same for long in the modern game, but Clark gave his endorsement to rule changes announced by the NRL last week.

"From a referee's perspective they have ample opportunity to do skill sessions to ensure that come the start of the season, they're ready to go and they're right across the new rules," Clark said.

"I think the rule changes they've brought in this year are ones that will make the game an even better spectacle. It's good for referees as well, it keeps them on their toes and keeps them reinventing themselves."